Surgical stapling instrument with articulated stapling head assembly on rotatable and flexible support shaft

ABSTRACT

An improved surgical instrument is provided for applying surgical fasteners, such as staples, to human tissue which is particularly suited for applying one or more rows of fasteners across a tissue lumen. The surgical instrument can be used in thoracic and abdominal surgical procedures where access to the surgical site is restricted. The surgical instrument includes an articulated fastener applying assembly mounted on a rotatable and flexible support shaft assembly to provide more convenient access to restricted surgical sites. The fastener applying assembly has a compact construction including a fixed jaw which supports a fastener cartridge and a movable jaw which supports an anvil for clamping the tissue therebetween. The fastener applying assembly includes a pin placement mechanism which is actuated by the movable jaw to control the movement of a tissue retaining pin on the fixed jaw. A dual cam mechanism is provided for driving the fasteners into the tissue clamped between the anvil and the fastener cartridge. The instrument has an actuator handle assembly with an improved actuator mechanism for closing the jaws and driving the fasteners into the tissue.

FIELD OF THE INVENTION

The present invention generally relates to a surgical instrument forapplying surgical fasteners to tissue and, more particularly, to asurgical stapling instrument with an articulated stapling head assemblymounted on a rotatable and flexible support shaft to provide moreconvenient access to restricted surgical sites. Also, this inventionrelates to a linear surgical stapling instrument including an improvedstapling head assembly which is compact in construction and to animproved actuator handle assembly for closing and firing the staplinghead assembly.

BACKGROUND OF THE INVENTION AND PRIOR ART

In recent years, there has been an increasing number of surgeons usingsurgical staples, rather than conventional sutures. This is true becausethe use of surgical staples and surgical stapling instruments has mademany difficult procedures much simpler to perform. Of more importance,however, is that the use of surgical staples significantly reduces thetime required for most procedures, and therefore reduces the length oftime which the patient must be maintained under anesthetic. Many typesof surgical stapling instruments have been devised for differentsurgical procedures.

The present invention is directed to a surgical instrument for applyingsurgical fasteners to internal organs and tissues such as the lung,esophagus, stomach, duodenum, and intestines. The invention is embodiedin a linear surgical stapler which permits access to restricted surgicalsites, e.g., the pelvic area of the human body.

In its earliest form, the linear surgical stapling instrument was apermanent, multi-use instrument and the surgical staples were manuallyloaded into the instrument one at a time. An example of a surgicalstapling instrument of this type is disclosed in U.S. Pat. No.3,080,564. This type of instrument was, in general, complex inconstruction, expensive to manufacture, heavy, bulky and difficult toboth load the surgical staples and to clean and sterilize after eachuse. A subsequent improvement in linear surgical stapling instrumentswas the provision of presterilized, disposable loading units or staplecartridges. U.S. Pat. Nos. 3,275,211, 3,315,863 and 3,589,589 discloseexamples of permanent, multi-use linear instruments having replaceablestaple cartridges.

Several types of surgical fastener applying instruments are known forapplying surgical fasteners to body tissue clamped between relativelymovable fastener holding and anvil portions of the instrument. Thesurgical fasteners may be metal staples as shown, for example, in U.S.Pat. No. 3,275,211, or consist of non-metallic resinous materials asshown, for example, in U.S. Pat. No. 4,402,445. In the case of metalstaples, the staple legs are typically driven through the tissue andformed by the anvil to secure the staples in the tissue. In the case ofnon-metallic fasteners, each fastener may initially consist of twoseparate parts, i.e., a fastener part disposed in the fastener holdingpart of the apparatus, and a retainer part disposed in the anvil part ofthe apparatus. The leg or legs of the fastener parts are driven throughthe tissue and interlock with the retainer parts to secure the fastenersin the tissue. Although most surgical staples are biologically inert andremain permanently in the body, biologically absorbable metal surgicalstaples are known. Surgical fasteners of non-metallic resinous materialscan also be made either biologically absorbable or non-absorbable.

The surgical instrument of the present invention is not limited to usewith any particular type or form of fasteners. The various surgicalfasteners mentioned above represent examples of the types of fastenerswhich can be used with the instrument of the present invention. Thus, asused herein, surgical fastener is meant to be generic to all of theabove fasteners, including both staples and two-part devices. Similarly,as used herein, fastener holder and anvil are terms which are generic tosurgical instruments for applying the above types of fasteners.

In the prior instruments disclosed in U.S. Pat. Nos. 3,275,211 and4,402,445 for applying surgical fasteners to tissue clamped between thefastener holding and anvil portions of the instrument, a distal fastenerapplying assembly is rigidly connected to the proximal actuator portionof the instrument. More recently, however, there has been increasinginterest in instruments in which the connection between the fastenerapplying assembly and the actuator assembly is not completely rigid.U.S. Pat. No. 4,473,077, for example, shows a surgical stapler in whichthe shaft assembly connected between the fastener applying andactuator-assemblies is transversely flexible in a single plane.

Also, in view of rising hospital costs, there has been an everincreasing interest in disposable surgical stapling instruments toeliminate as much work as possible, i.e., disassembly, cleaning,reassembly, sterilization and the like, and to be more efficient, whileat the same time, not having to compromise the surgical procedures. U.S.Pat. Nos. 4,354,628, 4,383,634 and 4,527,724, for example, each disclosedisposable linear surgical stapling instruments.

U.S. Pat. Nos. 4,566,620, 4,728,020 and 4,869,414, disclose otherexamples of instruments for applying surgical fasteners to tissueclamped between the fastener holding and anvil portions of theinstrument. An articulated surgical fastener applying apparatus isdisclosed in U.S. Pat. No. 4,566,620 in which the fastener applyingassembly is rotatably mounted at the distal end of a longitudinal shaftassembly by a joint for allowing rotation of the fastener applyingassembly relative to the actuator assembly about each of three mutuallyorthogonal axes. U.S. Pat. Nos. 4,728,020 and 4,869,414 each disclose anarticulated surgical fastener applying apparatus including a fastenerapplying assembly mounted at the distal end of a longitudinal shaftassembly for pivotal movement about an axis transverse to thelongitudinal axis of the shaft assembly which is substantiallyinflexible about all other axes parallel to the transverse axis. Theshaft assembly is rotatably mounted on a proximal actuator assembly toallow rotation of the fastener applying assembly relative to theactuator assembly about the longitudinal axis of the shaft assembly. Onedrawback of these instruments is that the access of the fastenerapplying assembly into the pelvic area is restricted by the relativelylarge dimensions of the fastener holding portions of the instruments.Also, the fastener applying assembly of these instruments includesprotruding latch buttons and alignment pin carriers which further limitthe access of the fastener applying assembly into the pelvic area.

Additional examples of surgical instruments including a fastenerapplying assembly provided with relatively movable fastener holding andanvil portions are disclosed in U.S. Pat. Nos. 4,591,085 and 4,941,623.The instrument disclosed in U.S. Pat. No. 4,591,085 includes a triggerinterlocking mechanism which precludes the actuation of the triggeruntil an appropriate gap is set between the jaws of the instrument.

U.S. Pat. No. 4,938,408 discloses a surgical stapling instrumentincluding a rotatable support shaft on which a stapler head is rotatablymounted for rotation about an axis normal to the axis of the supportshaft. U.S. Pat. No. 5,137,198 discloses a linear surgical staplinginstrument including a fast jaw closure mechanism and a trigger safetydevice.

In co-pending U.S. patent application Ser. No. 832,299, filed on Feb. 7,1992, entitled "Surgical Anastomosis Stapling Instrument With FlexibleSupport Shaft And Anvil Adjusting Mechanism", assigned to the sameassignee as the present invention, a surgical stapling instrumentincluding a flexible shaft assembly is disclosed. The flexible shaftassembly comprises a pair of elongated helical elements which areconcentrically wound together with the coils of the first helicalelement alternately interspersed with the coils of the second helicalelement. Each coil of the first helical element has a round crosssection and each coil of the second helical element has a triangularcross section provided with sloped surfaces which slidably engage theadjacent round coils. There is, however, no disclosure of any mechanismto limit the bending of the flexible shaft assembly.

SUMMARY OF THE INVENTION

The present invention achieves an improved surgical instrument forapplying surgical fasteners, such as staples, to human tissue which isparticularly suited for applying one or more rows of fasteners across atissue lumen to produce a fluid tight closure of the lumen. The surgicalinstrument of this invention is intended for use in thoracic andabdominal surgical procedures in which single fire surgical staplers arecurrently used and where access to the surgical site is restricted. Forexample, the surgical instrument can be used in the following types ofprocedures: (1) a double stapling technique, especially for a lowanterior re-section, (2) closure of the bronchus during a lobectomy orpneumonectomy, (3) closure of the esophagus in esophageal procedures,and (4) closure of the pulmonary blood vessels during a lobectomy orpneumonectomy.

The surgical instrument of the present invention comprises a shaftassembly including a support shaft section and a flexible shaft sectionfor mounting a fastener applying assembly on an actuator handleassembly. The fastener applying assembly includes a fastener holder forapplying one or more surgical fasteners, an anvil for clamping thetissue against the anvil holder, and a driver for driving the fastenersfrom the fastener holder into the tissue clamped by the anvil againstthe fastener holder. The actuator handle assembly includes means foractuating the driver. The flexible shaft section of the shaft assemblyis adapted to be bent in any radial direction relative to thelongitudinal axis of the shaft assembly, e.g., into a curvedconfiguration. The flexible shaft section is designed to retain its bentor curved shape and to resist deflection when the surgical instrument isoperated. The flexible shaft section is limited to a predetermined rangeof bending angles relative to the longitudinal axis of the shaftassembly.

In a preferred embodiment of the surgical instrument, the flexible shaftsection is located at the distal end of the shaft assembly adjacent tothe fastener applying assembly. A pivot connection is provided at thedistal end of the shaft assembly for supporting the fastener applyingassembly to pivot about an axis transverse to the longitudinal axis ofthe shaft assembly. The pivot connection includes detent means formaintaining the fastener applying assembly in predetermined angularorientations relative to the longitudinal axis of the shaft assembly.Preferably, the shaft assembly is rotatable about its axis to orient thefastener applying assembly in different angular orientations relative tothe actuator handle assembly. The instrument includes means for lockingthe shaft assembly in different angular orientations relative to theactuator handle assembly.

By bending the flexible shaft section into an appropriate configuration,the surgeon can insert the fastener applying assembly at a surgicalsite, e.g., into the pelvic area, where access is restricted. Byrotating the shaft assembly on its axis and pivoting the fastenerapplying assembly about the transverse axis of the pivot connection, thesurgeon can locate the fastener applying assembly in a convenientorientation for clamping the tissue between the fastener holder and theanvil and for actuating the surgical instrument without interferencefrom the viscera or the body wall.

In accordance with another aspect of the invention, a surgical staplinginstrument for applying one or more surgical staples to tissue comprisesa stapling head assembly including a first jaw which supports a stapleholder for receiving one or more surgical staples, a second jaw whichsupports an anvil for clamping the tissue against the staple holder whenthe jaws are closed, and a staple driver for driving the staples fromthe staple holder into the tissue and against the anvil, an actuatorhandle assembly including a jaw closure lever for closing the jaws tomove the anvil into a tissue clamping position and a staple firingtrigger for actuating the staple driver, and a shaft assembly formounting the stapling head assembly on the actuator handle assembly. Thestapling head assembly includes a tissue retaining pin mounted insideone of the jaws which is movable from a retracted position within theone jaw when the jaws are open to an extended position engaging theother jaw when the jaws are closed. The other jaw includes actuatormeans for moving the tissue retaining pin between the retracted andextended positions.

Preferably, the tissue retaining pin is mounted on a cantilever springarm which supports the tissue retaining pin for movement between theretracted and extended positions. A pin placement arm is pivotallymounted inside the same jaw which supports the tissue retaining pin forengaging the cantilever spring arm and moving the tissue retaining pinfrom the retracted position to the extended position. The pin placementarm includes a cam projecting laterally therefrom and extending througha window formed in the jaw. A cam actuator finger is provided on theother jaw for engaging the cam when the jaws are closed to pivot the pinplacement arm and move the retaining pin from the retracted position tothe extended position.

In the case of a linear surgical stapler, the tissue retaining pin, thecantilever spring arm, and the pin placement arm are mounted inside theproximal jaw which supports the staple holder. The laterally projectingcam on the pin placement arm is actuated by the cam actuator fingermounted on the distal jaw which supports the anvil. Also, it iscontemplated that the tissue retaining pin, the spring arm and the pinplacement arm can be mounted on the distal jaw and the cam actuatorfinger can be mounted on the proximal jaw.

No portion of the tissue retaining pin protrudes from the stapling headassembly with the anvil and staple holder in the open or unclampedposition. Thus, the tissue retaining pin does not interfere with theplacement of the stapling head assembly in a desired orientation at arestricted surgical site. Also, no portion of the actuator mechanism forthe tissue retaining pin, except for the laterally projecting cam,protrudes from the stapling head assembly. Thus, the pin actuatormechanism does not interfere with the desired placement of the staplinghead assembly at the restricted surgical site.

In accordance with another aspect of the invention, the surgicalstapling instrument includes a closure cable extending through the shaftassembly for pulling the distal jaw toward the proximal jaw when the jawclosure lever is actuated, a firing cable extending through the shaftassembly for actuating the staple driver when the staple firing triggeris actuated, and a pivot connection at the distal end of the shaftassembly for supporting the stapling head assembly to pivot about anaxis transverse to the longitudinal axis of the shaft assembly which isadapted to slidably receive the closure cable and to provide a path ofsubstantially constant length for the closure cable as the stapling headassembly is pivoted relative to the shaft assembly. In addition, each ofthe cables is adapted to maintain a substantially constant length whenthe shaft assembly is rotated about its axis. Preferably, each of thecables has a multi-filament counter-twisted construction to resistchanges in length when the shaft assembly is rotated about its axis. Ina preferred embodiment of the cable construction, each of the cablescomprises a plurality of strands twisted together in a first helicaldirection, and each of the strands comprises a plurality of filamentstwisted together in a second helical direction opposite to the firsthelical direction.

Another feature of the invention relates to a cam actuator mechanism foractuating the staple driver with different mechanical advantages whenthe staple firing trigger is actuated. The cam actuator mechanism isadapted to actuate the staple driver with a first mechanical advantageover a first portion of the stroke of the staple firing trigger and witha second mechanical advantage over a second portion of the stroke of thestaple firing trigger. In a preferred embodiment of the cam actuatormechanism, a firing cam is secured to the firing cable and slidablymounted on one of the jaws by one or more guide pins formed thereonwhich are slidably received in inclined cam slots formed on the jaw. Acam actuator surface on the firing cam engages a cam follower surface onthe staple driver. The staple driver is advanced by movement of theguide pins in the inclined cam slots and by relative movement of the camactuator surface along the cam follower surface when the firing cam isactuated by the firing cable.

The cam actuator mechanism has a compact construction which enables thestapling head assembly to be reduced in size in comparison with theprior art. This compact construction allows the stapling head assemblyto be positioned more easily at restricted surgical sites, e.g., in thepelvic area.

A further aspect of the invention relates to an improved actuatormechanism comprising a jaw closure lever for closing the jaws of thesurgical instrument to move the anvil into a tissue clamping positionand a staple firing trigger for actuating the staple driver. The jawclosure lever is pivotally mounted on the actuator assembly for movementfrom an open position to a closed position to close the jaws and thestaple firing trigger is pivotally mounted on the jaw closure lever. Adeployment mechanism is provided for deploying the staple firing triggerin an inoperative position with the jaw closure lever in its openposition and in a firing position when said jaw closure lever is movedfrom its open position to its closed position. The staple firing triggeris actuatable from its firing position to actuate the staple driver. Thedeployment means prevents actuation of the staple firing trigger untilthe jaw closure lever is moved to its closed position and permitsactuation of the staple firing trigger after the jaw closure lever ismoved to its closed position. Preferably, the stapling instrumentincludes means for locking the firing trigger to the jaw closure leverafter actuation of the firing trigger to provide a visual indicationthat the stapling instrument has been fired.

A preferred embodiment of the surgical instrument comprises a linearstapling instrument for applying one or more surgical staples to thetissue. Preferably, the stapling instrument has a stapling head assemblyincluding a fixed jaw which supports a staple holder adapted to receivea plurality of surgical staples arranged in one or more rows and amovable jaw which supports an anvil for clamping the tissue against thestaple holder when the jaws are closed. Jaw coupling means is providedfor slidably and pivotally coupling the movable jaw to the fixed jaw.The jaw coupling means includes a slidable roller pin slidably androtatably mounted in guide slots formed in each of the jaws.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, aspects and advantages will be betterunderstood from the following detailed description of the preferredembodiments of the invention with reference to the drawings, in which:

FIG. 1 is a perspective view of a surgical stapling instrumentconstructed in accordance with this invention which includes a supportshaft with a flexible section for mounting a stapling head assembly onan actuator handle assembly;

FIG. 2 is a side elevation of the surgical stapling instrument of FIG.1;

FIG. 3 is a partially cutaway side view of the surgical staplinginstrument of FIG. 2 in a bent configuration to adjust the orientationof the stapling head assembly;

FIG. 4 is an enlarged, partially cutaway side view showing the flexiblesection of the support shaft of the surgical stapling instrument of FIG.2;

FIG. 5 is an enlarged partially cutaway side elevation showing analternative embodiment of the flexible section of the support shaft;

FIG. 6 is a partially cutaway side elevation showing an actuatormechanism contained within the actuator handle assembly of FIG. 2;

FIG. 7 is a partially cutaway side elevation showing a set of cam slotsformed in the stapling head assembly of FIG. 2;

FIG. 8 is a partially cutaway side elevation showing a control linkageof the actuator mechanism of FIG. 6;

FIG. 9 is a partially cutaway side elevation showing a tissue retainingpin and a placement arm within the stapling head assembly of FIG. 2;

FIG. 10 is a partially cutaway side elevation showing a stapling firingtrigger of the actuator mechanism of FIG. 6;

FIG. 11 is an enlarged longitudinal section showing a sliding cammechanism within the stapling head assembly of FIG. 2;

FIG. 12 is an enlarged longitudinal section showing a portion of theflexible support shaft of FIG. 5 in a straight condition;

FIG. 13 is an enlarged longitudinal section showing a portion of theflexible support shaft of FIG. 5 in a bent condition;

FIG. 14 is an exploded perspective view of the actuator mechanism ofFIG. 6;

FIG. 15 is a partially cutaway side view showing the operation of theactuator mechanism of FIG. 6;

FIG. 16 is a partially cutaway side view showing the stapling headassembly of FIG. 2 in a partially closed position;

FIG. 17 is a partially cutaway side view showing the stapling headassembly of FIG. 2 in a fully closed position.

FIG. 18 is an exploded perspective view showing the components of thestapling head assembly;

FIG. 19 is an enlarged, partially cutaway proximal end view of themovable jaw which supports the anvil of the stapling head assembly;

FIG. 20 is an enlarged, partially cutaway distal end view of the fixedjaw which supports the staple cartridge of the stapling head assembly;

FIG. 21 is an enlarged, partially cutaway top view of the stapling headassembly;

FIG. 22 is an enlarged, fragmentary section view of the stapling headassembly along line 22--22 of FIG. 16;

FIG. 23 is an enlarged, partially cutaway side view of the staplecartridge of the stapling head assembly;

FIG. 24 is an enlarged vertical section of the staple cartridge alongline 24--24 of FIG. 23;

FIG. 25 is an enlarged front or distal end view of the staple driver ofthe stapling head assembly;

FIG. 26 is a side view of the staple driver of FIG. 25;

FIG. 27 is a longitudinal section of the staple driver along line 27--27of FIG. 25;

FIG. 28 is a longitudinal section of the staple driver along line 28--28of FIG. 26;

FIG. 29 is a side view of a metal insert for the staple driver of FIGS.25-28;

FIG. 30 is an enlarged front view of a control knob mounted at thedistal end of the actuator handle assembly;

FIG. 31 is an enlarged vertical section along line 31--31 of FIG. 8showing a pair of locking fingers on the actuator handle assemblyactuated by the control knob;

FIG. 32 is an enlarged, partially cutaway vertical section showing afirst row of staples in the stapling head assembly with the jaws open toreceive a tissue lumen therebetween;

FIG. 33 is an enlarged, partially cutaway vertical section showing asecond row of staples in the stapling head assembly with the jawspartially closed to capture the tissue lumen therebetween;

FIG. 34 is an enlarged, partially cutaway vertical section of thestapling head assembly with the jaws closed and the staples advancedthrough the tissue lumen into contact with the anvil;

FIG. 35 is an enlarged, partially cutaway vertical section of thestapling head assembly with the jaws closed and the staples drivenagainst the anvil and formed into a B-shaped configuration;

FIG. 36 is an enlarged vertical section of a knuckle housing whichprovides a pivot connection for the stapling head assembly;

FIG. 37 is a bottom view of the knuckle housing of FIG. 36;

FIG. 38 is an enlarged front view of a knuckle pin pivotally supportedby the knuckle housing of FIG. 36;

FIG. 39 is a side view of the knuckle pin of FIG. 38;

FIG. 40 is a rear view of the knuckle pin of FIG. 38;

FIG. 41 is an enlarged partially cutaway top view of the knuckle pin ofFIG. 39;

FIG. 42 is an enlarged partially cutaway section view of the knuckle pinalong line 42--42 of FIG. 39;

FIG. 43 is an enlarged, partially cutaway section view of the knucklehousing along line 43--43 of FIG. 36;

FIG. 44 is an enlarged, partially cutaway bottom view of the knucklehousing of FIG. 36;

FIG. 45 is an enlarged, partially cutaway section view of the pivotconnection showing the knuckle pin pivoted in the knuckle housing;

FIG. 46 is an enlarged perspective view showing the multiple strandconstruction of the cables of the stapling instrument;

FIG. 47 is an enlarged perspective view showing the multiple filamentsof each strand of the cables; and

FIG. 48 is an enlarged fragmentary section of the support shaft alongline 48--48 of FIG. 4.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, the present invention is embodied in a surgicalstapling instrument, generally 50, which includes a distal stapling headassembly 60 connected by a support shaft assembly 70 to a proximalactuator handle assembly 80. The stapling head assembly 60 includes aproximal or fixed jaw 62 which supports a staple cartridge 64 and adistal or movable jaw 66 which supports a staple forming anvil 68 (FIG.2). The staple cartridge 64 receives one or more rows of staples 65(FIG. 28) which are driven against the anvil 68 and formed into aB-shaped configuration to fasten tissue together. For example, nineteenstaples are held in the staple cartridge 64 and arranged in twostaggered rows. It will be understood by persons skilled in the art thatthe surgical stapling instrument 50 can be adapted to operate withtwo-part surgical fasteners instead of the staples 65.

As shown in FIG. 1, the proximal or fixed jaw 62 is mounted in ahinge-like fashion on a pivot connection 72 which permits the staplinghead assembly 60 to pivot about a vertical axis 52 into differentangular orientations relative to a centerline or longitudinal axis 54 ofthe support shaft assembly 70. For example, the pivot connection 72 isarranged to allow the stapling head assembly 60 to pivot about thevertical axis 52 in approximately 20° increments. The articulatedstapling head assembly 60 is pivotable either clockwise orcounterclockwise about the vertical axis 52 to positions oriented atabout ±20°, ±40°, ±60° and ±80° relative to the longitudinal axis orcenterline 54. The support shaft assembly 70 is rotatably mounted on theactuator handle assembly 80 for rotation about the longitudinal axis orcenterline 54. Preferably, the support shaft assembly 70 is rotatableover an angular range of approximately 340° or more about the centerline54. A control knob 82 is rotatably mounted at the distal end of theactuator handle assembly 80 to allow the support shaft assembly 70 to beunlocked for rotation and to be locked in any desired rotationalorientation.

The shaft assembly 70 includes a tubular support shaft 74 rotatablymounted on the actuator handle assembly 80 and secured by a couplingsleeve 75 to a flexible tubular shaft 76. The flexible tubular shaft 76is capable of bending in any radial direction relative to the centerline54 of the shaft assembly 70 into a bent or curved shape (FIG. 3). Thehinge-like pivot connection 72 is mounted on a coupling sleeve 78 at thedistal end of the flexible shaft 76. The tubular support shaft 74, thecentral coupling sleeve 75, and the distal coupling sleeve 78 can bemade of metal, e.g., aluminum.

The actuator handle assembly 80 includes a pivotally mounted closurelever 84 for closing the movable jaw 66 toward the fixed jaw 62 to clampa tubular section of tissue between the jaws 62 and 66. The actuatorhandle assembly 80 also includes a pivotally mounted firing trigger 86for actuating the stapling head assembly 60 to drive the staples fromthe staple cartridge 64 through the tissue and to form the staplesagainst the anvil 68. A firing safety lever 88 is pivotally mounted onthe closure lever 84. With the firing safety lever 88 in its latchedposition (FIG. 2), the staple firing trigger 86 is locked againstmovement relative to the closure lever 84 to prevent the firing of thestaples in the staple cartridge 64.

As shown in FIG. 1, the actuator handle assembly 80 includes a pair ofhollow handle sections 90 and 92 made of plastic material and adapted tosnap fit together. Each of the handle sections 90 and 92 includes adepending handle grip 96. The depending handle grips 96 provide a hollowchannel 98 therebetween for receiving the closure lever 84 when it isactuated to close the stapling head assembly 60.

Referring to FIGS. 1 and 30, the control knob 82 has two radiallyprojecting longitudinal fins 83 at diametrically opposed positions and aseries of longitudinal ribs 85 uniformly spaced about its circumference.The fins 83 and ribs 85 act as finger grips to facilitate the manualrotation of the control knob 82 by the surgeon. The control knob 82 ismounted for rotation over a range of approximately 90° about thelongitudinal axis 54 of the support shaft assembly 70. A pair of cams 87(FIG. 30) is located at diametrically opposed positions inside thecontrol knob 82. The cams 87 are arranged to actuate a pair of resilientlocking fingers 91 and 93 (FIG. 31) on the handle sections 90 and 92,respectively. The locking fingers 91 and 93 include a series ofserrations or teeth 97 and 99, respectively, which are adapted to engagea set of circumferential teeth 77 on the outside of the tubular shaft74. With the control knob 82 rotated to its locked position, theflexible locking fingers 91 and 93 are engaged by the cams 87 and areretained in engagement with the circumferential teeth 77 to lock thetubular shaft 74 against rotation. When the control knob 82 is rotatedto its unlocked position, the cams 87 are disengaged from the lockingfingers 91 and 93 which can be deflected away from the circumferentialteeth 77 when the tubular shaft 74 is rotated relative to the actuatorhandle assembly 80.

In the preferred embodiment, the rotation of the shaft assembly 70 isconstrained to the range of about ±170 degrees by a raised tab 79 (FIG.6) on the tubular shaft 74 which is engageable with an end stop (notshown) on each of the handle sections 90 and 92 to limit the amount ofrotation. The circumferential teeth 77 on the tubular shaft 74 and thelocking fingers 91 and 93 provide a detent mechanism which definestwenty-two angular positions for rotation of the shaft assembly 70.

A longitudinal indicator flange 95 (FIG. 1) is formed at the top of thehandle section 92 adjacent to the control knob 82. In the lockedposition, one of the fins 83 on the control knob 82 is aligned with theflange 95 to indicate that the tubular shaft 74 is locked againstrotation. In the unlocked position, the fins 83 on the control knob 82are rotated to a position about 90° from the flange 95 to indicate thatthe tubular shaft 74 is free to rotate.

Referring to FIGS. 1 and 14, the actuator handle assembly 80 includes anactuator mechanism, generally 100, contained within the hollow plastichandle sections 90 and 92. Preferably, the components of the actuatormechanism 100 consist of a rigid material, for example, a metal such asstainless steel. The actuator mechanism 100 includes a pair of outerchassis plates 102 which are similar in shape to the handle sections 90and 92. Each of the handle sections 90 and 92 is provided with a set ofinternal flanges and ribs which support the chassis plates 102 in afixed position within the actuator handle assembly 80 when the handlesections 90 and 92 are snap fit together. The chassis plates 102 arefastened together in a spaced parallel relationship by a pair oftransverse connecting pins 104 located adjacent to the distal ends ofthe chassis plates 102 and by a pair of connecting pins 106 extendingtransversely between a pair of depending grip portions 108 of thechassis plates 102. An upper connecting pin 110 joins the top distalportions of the chassis plates 102 together and pivotally supports theother components of the actuator mechanism 100. A pair of opposed,hollow semi-cylindrical cylindrical flanges 112 extend axially from thedistal ends of the chassis plates 102 for receiving the tubular supportshaft 74 therebetween.

The actuator mechanism 100 includes a pair of closure lever plates 114each including a pivot hole 116 for receiving the connecting pin 110 topivotally support the closure lever plates 114 for pivotal movementrelative to the chassis plates 102. The closure lever plates 114 aresecured together in a spaced parallel relationship by a transverseconnecting pin 118 which rotatably supports a pulley 120. The closurelever plates 114 include elongated depending lever portions 122 whichare contained inside a hollow plastic closure lever shroud 124 (FIG. 6)to provide the jaw closure lever 84 of the actuator handle assembly 80.

As shown in FIG. 14, a firing trigger plate 126 is pivotally mountedbetween the closure lever plates 114 by a pair of transverse pivot pins128 (one shown) extending from its opposite sides and rotatably receivedin a pair of pivot holes 130 (one shown) formed in the closure leverplates 114. The firing trigger plate 126 is mounted within a hollowplastic firing trigger shroud 132 (FIG. 6) to provide the staple firingtrigger 86 of the actuator handle assembly 80. The firing trigger plate126 has an enlarged proximal end portion 134 provided with a pair offiring lever deployment pins 136 extending transversely from itsopposite sides and slidably received in a pair of arc-shaped slots 138(one shown) formed in the closure lever plates 114. The outer ends ofthe firing lever deployment pins 136 extend through the slots 138 into apair of firing lever deployment cam slots 140 formed in the chassisplates 102. A finger 142 on the enlarged proximal portion 134 of thetrigger firing plate 126 defines an anchor hole 144 for receiving ananchor 146 secured to the proximal end of a firing cable 148 (FIG. 10).Initially, the cable 148 extends loosely around the pulley 120 and overthe pivot pin 110. The cable 148 passes under the upper connecting pin104 and through a vertical slot 150 formed in a stop plate 151 locatedon the distal side of the connecting pins 104. The stop plate 151includes a pair of tabs 152 projecting laterally from its opposite sidesand received in a pair of mounting holes 153 formed in the chassisplates 102. When the staple firing trigger 86 is actuated, the slack inthe cable 148 is taken up by the enlarged proximal end portion 134 ofthe trigger firing plate 126.

The actuator mechanism 100 includes a closure control linkage, generally154, comprising a link 155 and a fork plate 156 pivotally connectedtogether by a pair of transverse pivot pins 158 extending in oppositedirections from the lower end of the link 155. The outer ends of thepivot pins 158 extend into a pair of Z-shaped guide slots 160 (oneshown) formed in the chassis plates 102. Each of the guide slots 160includes an upper distal section 161 and a lower proximal section 162which overlap and define a detent or shoulder 159 in the guide slot 160.A pair of transverse pivot pins 163 (one shown) at the upper end of thelink 155 extend transversely in opposite directions from the link 155.The pivot pins 163 are received in a pair of pivot holes 164 formed in apair of depending distal fingers 165 on the closure lever plates 114.Each finger 165 is inclined downwardly and forwardly to define aninverted V-shaped notch 166 behind the finger 165. A closure cable 170extends through a slot 167 at the front of the closure fork plate 156.The proximal end of the closure cable 170 is secured to an anchor 168which is inserted through an assembly hole 169 at the proximal end ofthe slot 167 and engages the inside of the fork plate 156. The closurecontrol linkage 154 applies tension to the closure cable 170 when theclosure lever plates 114 are actuated by the closure control lever 84.The closure cable 170 extends over the lower coupling pin 104 andthrough the vertical slot 150 formed in the stop plate 151.

Referring to FIGS. 2 and 4, the flexible tubular support shaft 76comprises a dual helical coil structure comprising a first elongatedhelical member 172 and a second elongated helical member 174 which areconcentrically wound together with the coils 176 of the first helicalmember 172 alternately interspersed with the coils 178 of the secondhelical member 174. As shown in FIG. 4, each coil 176 of the helicalmember 172 has a round cross section. Each coil 178 of the helicalmember 174 has a triangular, wedge-shaped cross section defining a pairof inwardly sloped surfaces 180 which engage the round exterior surfacesof the adjacent round coils 176. The wedge-shaped coils 178 arepositioned between the round coils 176 to maintain a desired separationbetween the adjacent round coils 176 and to maintain the first helicalmember 172 in tension. Each of the triangular coils 178 has a roundedouter surface to prevent the trapping of surgical gloves during use ofthe surgical stapling instrument 50. The helical coil members 172 and174, which are preferably made of stainless steel, allow the flexibleshaft 76 to be bent in any radial direction relative to the longitudinalaxis or centerline 54 of the support shaft assembly 70. Inside thehelical coil members 172 and 174 is a concentrically mounted cablesupport tube 182, preferably made of a malleable metal such as aluminum,which allows the flexible shaft 76 to assume its bent or curved shape.The cable support tube 182 is flexible in any radial direction relativeto the longitudinal axis or centerline 54 of the support shaft assembly70. The cable support tube 182 enables the flexible support shaft 76 toassume its curved configuration and to resist tension from the cables148 and 170 when the stapling head assembly 60 is actuated.

In the preferred embodiment, the flexible support shaft 76 is adapted tobe bent within a predetermined range, e.g., up to about ±30° in anydirection from its straight configuration. After bending, the flexiblesupport shaft 76 maintains its bent shape until further manipulated. Themalleable cable support tube 182 prevents the bent support shaft 176from inadvertently straightening. This shape retention feature permitsaccess of the stapling head assembly 60 into the pelvic cavity whileavoiding contact of the actuator handle assembly 80 with the viscera orbody wall. The helical coil members 172 and 174 provide a geometry suchthat the axis of the shaft assembly 70 remains a substantially constantlength during the bending of the flexible support shaft 76. This featureavoids any undesirable change in length which would result in motion ofthe taut cable system. The twin helical coil construction also providesa solid load path which resists the compressive forces during closureand firing while avoiding any tendency for the flexible support shaft 76to return to the straight condition.

In addition, the geometry of the circular coils 176 and the triangularcoils 178 is such that, at a bending angle of about 30°, one or theother of the coils becomes solid, i.e., either the adjacent round coils176 engage each other or the adjacent triangular coils 178 engage eachother. This condition causes a sharp increase in the force required tobend the flexible support shaft 76 and provides a limit on the extent ofthe bending motion. This limitation on the angle of bend keeps the cablefriction forces low so that the system operates in the regime ofsubstantially constant axis length. The malleable cable support tube 182is free to slide axially within the helical members 172 and 174 so thatany change in the length of the cable support tube 182 due to plasticdeformation does not effect the force required to bend the flexiblesupport shaft 76.

Referring to FIG. 5, in an alternative embodiment of the flexiblesupport shaft 76, the wedge-shaped coils 178 are reduced in widthcompared with the diameter of the round coils 176. Also, thewedge-shaped coils 178 are shaped to allow the adjacent round coils 176on the inside of the bend to engage each other when the flexible supportshaft 76 is bent to about a 30° bending angle. The helical coil springmember 172 and the helical wrap wire member 174 are coiled togetheralong a common longitudinal axis 175 with the round coils 176alternating with the triangular or wedge-shaped coils 178 and the coilspring member 172 in tension. The wrap wire member 174 is wrapped aboutthe coil spring member 172 with the wedge-shaped coils 178 positionedbetween the round coils 176 to maintain a desired separation between theadjacent round coils 176 when the support shaft assembly 76 is straight.The wedge-shaped coils 178 are forced between the adjacent round coils176 to maintain the coil spring member 172 in tension. The details ofthe flexible support shaft 76, the coil spring member 172, the wrap wiremember 174, the round coils 176 and the wedge-shaped coils 178 aredescribed in a co-pending U.S. patent application entitled "FlexibleSupport Shaft Assembly", filed on the same date and assigned to the sameassignee, Ethicon, Inc., as the present application, and hereinincorporated by reference.

As shown in FIG. 12, each of the wedge-shaped coils 178 initiallyseparates the adjacent round coils 176 longitudinally from each otherwhen the flexible support shaft 76 is straight. The round coils 176 andthe wedge-shaped coils 178 are aligned along the common longitudinalaxis 175. The wedge-shaped coils 178 are slidable relative to the roundcoils 176 to allow the flexible support shaft 76 to bend in a transversedirection relative to its longitudinal axis 175. The sliding action ofthe wedge-shaped coils 178 allows the flexible support shaft 76 to benduntil the round coils 176 on the inside of the bend engage each otherand limit the bending of the flexible support shaft 76.

Referring to FIG. 13, as the flexible support shaft 76 is benttransversely relative to its longitudinal axis 175, the wedge-shapedcoils 178 are shifted laterally relative to the adjacent round coils176. Also, the longitudinal axis 179 of the wedge-shaped coils 178 isshifted slightly relative to the longitudinal axis 175 of the roundcoils 176 in the direction of the bending of the flexible support shaft76. The portions of the round coils 176 on the inside of the bend movecloser together while the portions of the round coils 176 on the outsideof the bend move farther apart. As a result of the sliding action of thewedge-shaped coils 178 relative to the round coils 176, the flexiblesupport shaft 76 is bent into a curved configuration. The bending of theflexible support shaft 76 occurs without any substantial change in theoverall length of the flexible support shaft assembly 76 and withoutstretching of the coil spring member 172 along its axis 175 until theround coils 176 on the inside of the bend move into engagement with eachother. Up to this point, the bending of the flexible support shaft 76can be accomplished by applying a relatively small bending force to thecoil spring member 172 and the wrap wire member 174.

After the round coils 176 on the inside of the bend engage each other, asubstantially increased bending force must be applied to obtain anyfurther bending of the flexible support shaft 76 in the same direction.Because the portions of the round coils 176 on the inside of the bendare in contact with each other, any additional bending of the flexiblesupport shaft 76 requires the stretching of the coil spring member 172to move the portions of the round coils 176 on the outside of the bendfarther apart. Thus, the point at which the round coils 176 on theinside of the bend move into engagement with each other defines a limiton the bending of the support shaft 76 in the transverse direction.

Referring to FIG. 5, the dual coil structure of the flexible supportshaft assembly 76 with the clamping sleeves 184 is assembled in thefollowing manner. The wrap wire member 174 is wrapped about the coilspring member 172 to position the wedge-shaped coils 178 between theadjacent round coils 176 with the coil spring member 172 in tension. Aseries of clamping sleeves 184 made of compressible metal, e.g.,aluminum, is positioned at uniformly spaced locations along the coiledhelical members 172 and 174. Preferably, the clamping sleeves 184 arespaced apart by intervals of approximately three inches. Each of theclamping sleeves 184 is compressed or swaged mechanically to clamp thehelical members 172 and 174 together. Then, the helical members 172 and174 are divided into a plurality of flexible support shaft sections 76of uniform length by cutting the helical members 172 and 174 at themid-points of the clamping sleeves 184. Each of the resulting flexibletubular shaft sections 76 is clamped at its opposite ends by theclamping sleeves 184 to maintain the tension in the coil spring member102 and prevent the unraveling of the coiled helical members 172 and174.

Referring to FIG. 4, a double lumen cable support member 186 is mountedinside the cable support tube 182. The cable support member 186 has anelongated cylindrical configuration and extends from the distal end ofthe flexible support shaft 76 through the coupling sleeve 75 to a pointadjacent to the proximal end of the tubular support shaft 74. The cablesupport member 186 includes separate longitudinal passages 188 and 190(FIG. 48) for receiving the firing cable 148 and the closure cable 170,respectively.

The coupling sleeve 75 has an intermediate cylindrical wall 192 providedwith a central axial opening 194 for receiving the proximal end of thecable support tube 182. The clamping sleeve 184 at the proximal end ofthe flexible support shaft 76 is received and secured in a hollowcylindrical section 196 of the coupling sleeve 75. The distal end of thetubular support shaft 74 is received in a hollow cylindrical proximalsection 198 of the coupling sleeve 75. The distal end of the tubularsupport shaft 74 has a series of annular grooves 200 of reduced diameterwhich provide a series of longitudinally spaced annular ridges 202. Theproximal section 198 of the coupling sleeve 75 is deformed, e.g., bymagneforming, into contact with the annular grooves 200 and annularridges 202 to secure the coupling sleeve 75 to the tubular support shaft74.

Referring to FIG. 9, the pivot connection 72 which pivotally mounts thestapling head assembly 60 on the shaft assembly 70 comprises a knucklehousing 210 which is mounted on the flexible tubular support shaft 76 bythe coupling sleeve 78. The clamping sleeve 184 at the distal end of theflexible support shaft 76 is received in the distal coupling sleeve 78which is secured, e.g., by magneforming, to the clamping sleeve 84. Theknuckle housing 210 includes a pair of hollow, cylindrically shapedhinge arms 212 and 214 which receive a cylindrical knuckle pin 216 forrotation in a hinge-like fashion. A distally projecting flange 218 (FIG.11) is formed at the bottom of the knuckle pin 216. A passage 220extends radially through the knuckle pin 216 for slidably receiving theclosure cable 170. The knuckle housing 210 and the knuckle pin 216 arepreferably made of plastic material. The knuckle housing 210 is insertmolded onto an annular flange 79 projecting distally from the couplingsleeve 78 which is preferably made of aluminum.

The fixed jaw 62 includes a head plate 222, preferably made of metal,e.g., stainless steel, which is adapted to receive and support thestaple cartridge 64. The head plate 222 is formed as a double-walled,inverted channel-shaped member with a pair of opposed vertical sidewalls 224 which are mirror images of each other. The staple cartridge64, preferably made of plastic material, has a narrow rectangularconfiguration and is mounted at the front of the head plate 222 betweenthe side walls 224.

As shown in FIG. 7, the head plate 222 is pivotally supported by theknuckle housing 210 and the knuckle pin 216. The side walls 224 includean upper pair of flanges 226 which are curved inwardly toward each otherand are slidably received in an arcuate channel 228 (FIG. 11) formed atthe top of the knuckle housing 210. The side walls 224 also include alower pair of flanges 230 which are curved inwardly toward each otherand are rotatably received behind the knuckle pin 216 between the hingearms 212 and 214. With the knuckle pin 216 inserted into the cylindricalflanges 212 and 214, the head plate 222 is attached to the knucklehousing 210 in a hinge-like manner to pivotally support the staplinghead assembly 60 at the distal end of the support shaft assembly 70. Theside walls 224 of the head plate 222 include a pair of distallyprojecting side plates 232 which are spaced apart and secured togetherby a bearing pin 234. The lower flange 218 on the knuckle pin 216 isreceived between the side plates 232.

Referring to FIGS. 36 and 38, the knuckle pin 216 has a set of detents236 at its upper end which cooperate with a series of circumferentiallyspaced notches 237 on the interior of the upper hinge arm 212 to providea first detent mechanism for controlling the pivotal movement of theknuckle pin 216 relative to the knuckle housing 210. The knuckle pin 216also includes a set of detents 238 at its lower end which cooperate witha series of circumferentially spaced notches 239 formed on the interiorof the lower hinge arm 214 to provide a second detent mechanism forcontrolling the pivotal movement of the knuckle pin 216 relative to theknuckle housing 210. As shown in FIG. 41, there are three detents 236 atthe top of the knuckle pin 216 which are spaced 40° apart. The threedetents 236 cooperate with thirteen notches 237 (FIG. 43) which areuniformly spaced apart by 20° on the inside of the upper hinge arm 212.As shown in FIG. 42, there are six detents 238 at the bottom of theknuckle pin 216 which are uniformly spaced 60° apart. The six detents238 cooperate with eighteen notches 239 (FIG. 44) which are uniformlyspaced apart by 20° on the inside of the lower hinge arm 214. The upperand lower detents 236 and 238 on the knuckle pin 216 engage the notches237 and 239 on the interior of the upper and lower hinge arms 212 and214, respectively, to define 20° intervals for the pivotal movement ofthe stapling head assembly 60 about the vertical axis 52. The upperdetents 236 and notches 237 allow the stapling head assembly 60 to pivotover a range of about ±80° relative to the longitudinal axis 54.

As shown in FIG. 36, the knuckle housing 210 has an upper flange 241provided with an upwardly curved cable passage 243 for receiving thefiring cable 148. The curved passage 243 in the knuckle housing 210allows the firing cable 148 to turn smoothly at right angles as itpasses through the knuckle housing 210. The top of the knuckle pin 216has a beveled surface 245 (FIG. 39) which extends circumferentially overa range of about 200°. The beveled surface 245 provides a clearance forthe firing cable 148 and allows the knuckle pin 216 to rotate about itsaxis without interference with the firing cable 148.

Referring to FIGS. 38-40, the cable passage 220 in the knuckle pin 216is circular in shape for receiving the closure cable 170. The cablepassage 220 has opposite inner walls 247 (FIG. 42) which curve outwardlyin the proximal direction so that the cable passage 220 terminates at arearwardly facing slot 249 (FIGS. 39-40) on the proximal side of theknuckle pin 216. As shown in FIG. 45, the oppositely curved walls 247 ofthe passage 220 provide a path of substantially constant length for theclosure cable 170 as the knuckle pin 216 is rotated relative to theknuckle housing 210. This constant length feature tends to preventchanges in the tension on the closure cable 170 and changes in the gapbetween the staple cartridge 64 and the anvil 68 when the stapling headassembly 60 is rotated about the vertical axis 52 relative to thesupport shaft 70.

Referring to FIG. 9, the movable jaw 66 comprises a pair of generallyL-shaped jaw plates 240, preferably made of metal, e.g., stainlesssteel, each including a front arm 242 projecting upwardly from a basemember 244. A cam actuator finger 246 projects upwardly at the rear ofeach base member 244. The front arms 242 are secured together by a setof flush mount rivets 248 and are spaced apart by a hollow, generallyL-shaped pilot member 250 (FIG. 11), preferably made of plastic. Aninsert member 251 of rigid material, preferably a metal such asstainless steel, is mounted inside the pilot member 250 and connected tothe front arms 242 by the rivets 248. The metal insert 251 providesback-up stiffness for the plastic pilot member 250. The base members 244of the movable jaw plates 240 are secured together by a transverseconnecting pin 252. The staple forming anvil 68 has a pair of sideflanges 69 (FIG. 21) which receive the pilot member 250 and the metalinsert 251 therebetween. The L-shaped jaw plates 240 are secured to theside flanges 69 of the anvil 68 and to the pilot member 250 and theinsert member 251 by the flush mount rivets 248. The anvil 68 is offsetslightly in the proximal direction from the arms 242 to allow theelongated proximal edges 253 of the arms 242 to serve as cutting guidesfor a surgical knife or scalpel.

As shown in FIG. 7, the movable jaw 66 is slidably and pivotally mountedon the fixed jaw 62 in the following manner. The movable jaw plates 240are slidably and pivotally connected to the head plate 222 by a rolleror pivot pin 254 which is slidably and rotatably mounted in a pair ofelongated slots 256 formed in the side plates 232. The outer ends 255(FIG. 22) of the slidable roller or pivot pin 254 are reduced indiameter and are slidably received in a pair of elongated slots 258formed in the base members 244 of the movable jaw plates 240. The rolleror pivot pin 254 is both slidable and rotatable within the slots 256 and258 to provide a sliding and rolling pivot connection between the sideplates 232 and the base members 244 which reduces friction and allowsthe movable jaw 66 to slide and pivot into a closed position relative tothe fixed jaw 62. The outer ends 235 of the bearing pin 234 are reducedin diameter and are slidably received in a pair of guide slots 260formed adjacent to the distal ends of the base members 244. Each guideslot 260 includes a longitudinal section 261 and an upwardly inclinedsection 262. The bearing pin 234 and the guide slots 260 serve to guidethe movable jaw 66 into an upright position parallel to the fixed jaw 62when the stapling head assembly 60 is closed.

As shown in FIG. 11, the closure cable 170 extends through the knucklehousing 210 and the knuckle pin 216 and through a lower flange 264 onthe staple cartridge 64 into a hollow spring housing 266 projectinglaterally from the base of the pilot member 250. The closure cable 170extends through a depending flange 268 on the pilot insert 251 and isanchored in an opening 270 at the front of the pilot member 250 by ananchor 272 secured to the distal end of the closure cable 170 andengaged with the depending flange 268. A compression return spring 274extends between the depending flanges 264 and 268 to normally bias themovable jaw 66 to the open position. The closure cable 170 extendsthrough the return spring 274.

At the top of the movable jaw 66, a passage 276 extends longitudinallythrough the tip of the pilot member 250. A tissue retaining pin 280mounted on the fixed jaw 62 is received in the passage 276 when themovable jaw 66 is closed. The retaining pin 280 comprises an elongatedresilient wire spring which is bent into a narrow U-shaped retainer tip282 (FIG. 18) flanked by cantilever spring arms 284 which span thestaple cartridge 64. The spring arms 284 terminate in base portions 286which are inserted into a pair of slots 288 formed on opposite sides ofthe staple cartridge 64.

A pin placement arm 290 is pivotally mounted by a laterally projectingpivot pin 292 on each side of the staple cartridge 64. The pin placementarms 290 are positioned to engage the cantilever spring arms 284 of thetissue retaining pin 280. Each pin placement arm 290 includes awedge-shaped cam 294 which projects laterally outward from a window 296formed in each of the side walls 224 of the head plate 222. When themovable jaw 66 is closed, the cam actuator fingers 246 engage the cams294 to pivot the pin placement arm 290 counterclockwise, as viewed inFIG. 9, to advance the tissue retaining pin 280 from the fixed jawmember 62 into the passage 276 formed in the pilot member 250. Thetissue retaining pin 280 is also received in a notch 298 at the top ofthe anvil 68 to align the anvil 68 with the staple cartridge 64. Whenthe movable jaw member 66 is opened, the cantilever spring arms 284retract the tissue retaining pin 280 into the fixed jaw member 282.Also, the compression spring 274 (FIG. 11) returns the movable jawmember 66 to its open position.

As shown in FIG. 7, a plastic cover 300 is inserted between the verticalside walls 224 at the rear of the head plate 222. The cover 300 has apair of forwardly projecting side flaps 302 (FIG. 2) which provide anearmuff-like shield over the cams 294 projecting through the windows 296in the side walls 224. Each of the side flaps 302 includes an opening304 for receiving a prong 306 (FIG. 7) projecting laterally from each ofthe side walls 224 to fasten the cover 300 on the head plate 222. A pairof fastener pins 310 projecting laterally from opposite sides at the topof the staple cartridge 64 are received in a pair of angled slots 312formed in the side walls 224. The staple cartridge 64 is secured to theside walls 224 by a flush mount rivet 314 (FIG. 11) which extendstransversely through the depending flange 264 at the bottom of thestaple cartridge 64.

Referring to FIG. 11, a staple driver 320 is slidably mounted in thestaple cartridge 64 for driving the staples 65 against the anvil 68. Thestaple driver 320 is preferably made of plastic material and, ifdesired, consists of a solid molded plastic unit. The staple driver 320is actuated by a slidable firing cam 324 made of metal, e.g., stainlesssteel, which is slidably mounted on the fixed jaw 62 and secured to thedistal end of the firing cable 148.

The firing cam 324 forms part of a dual cam actuator mechanism foractuating the staple driver 320 with different mechanical advantageswhen the staple firing trigger 86 is actuated. The dual cam actuatormechanism is adapted to actuate the staple driver 320 with a firstmechanical advantage over a first portion of the stroke of the staplefiring trigger 86 and with a second mechanical advantage over a secondportion of the stroke of the staple firing trigger 86.

As shown in FIG. 7, the firing cam 324 includes a pair of laterallyprojecting pins 326 on each of its sides which are slidably received ina pair of inclined cam slots 328 formed in each of the side walls 224 ofthe head plate 222. The pins 326 and cam slots 328 provide a firstportion of the dual cam mechanism for actuating the staple driver 320.Each cam slot 328 is inclined downwardly toward the front of the headplate 222, e.g., at an angle of 15° from the vertical axis 52 (FIG. 1).Each of the cam slots 328 terminates in a bottom vertical portion 330oriented parallel to the vertical axis 52. As the firing cam 324 ispulled downwardly by the firing cable 148, the pins 326 ride along theinclined slots 328 so that the firing cam 324 and the staple driver 320are displaced in the distal direction.

Referring to FIG. 11, the firing cam 324 is contoured at its distal edgeto provide a pair of inclined cam actuator surfaces 332 which slidablyengage a complementary pair of inclined cam follower surfaces 334 formedat the proximal edge of the staple driver 320. The cam actuator surfaces332 and the cam follower surfaces 334 provide a second portion of thedual cam mechanism for actuating the staple driver 320. Preferably, bothpairs of inclined cam surfaces 332 and 334 are inclined at an angle of15° from the vertical axis 52. Each inclined cam actuator surface 332 onthe firing cam 324 terminates in a flat cam surface 336 orientedparallel to the vertical axis 52. Similarly, each inclined cam followersurface 334 on the staple driver 320 terminates in a flat cam followersurface 338 oriented parallel to the vertical axis 52. As the firing cam324 is pulled downwardly by the firing cable 148, the inclined camsurfaces 332 on the firing cam 324 ride along the inclined cam surfaces334 on the staple driver 320 to push the staple driver 320 distallyrelative to the firing cam 324. The flat cam surfaces 336 on the firingcam 324 are arranged to engage the flat cam surfaces 338 on the stapledriver 320 before the pins 326 on the firing cam 324 arrive at thebottom vertical portions 330 of the inclined slots 328. When the firingcam 324 is actuated, the first cam mechanism provided by the inclinedcam surfaces 332 and 334 bottoms out before the second cam mechanismprovided by the pins 326 and inclined slots 328.

The dual cam mechanism of the stapling head assembly 60 occupies lessspace than the staple firing mechanisms of the prior art. Thus, theouter dimensions of the fixed jaw 62 which houses the dual cam mechanismare minimized to allow the stapling head assembly 60 to accessrestricted surgical sites, e.g., in the pelvic area.

Generally, the surgical stapling instrument 50 is operated in thefollowing manner. With the jaws 62 and 66 open, the stapling headassembly 60 is articulated about the vertical axis 52 to a desiredangular position relative to the longitudinal axis 54. The flexibletubular shaft 76 is bent into a curved configuration to conform to theanatomy of the patient. The control knob 82 is rotated to its unlockedposition and the shaft assembly 70 is rotated about its longitudinalaxis 54 to orient the actuator handle assembly 80 in a comfortableposition for actuation by the surgeon. Then the control knob 82 isrotated to its locked position to lock the shaft assembly 70 againstrotation relative to the actuator handle assembly 80.

Next, by manipulating the surgical stapling instrument 50 in alever-like manner, the stapling head assembly 60 is positioned insidethe body and a tissue lumen 55 (FIG. 32) to be stapled is locatedbetween the open stapler jaws 62 and 66. The movable jaw 66 is partiallyclosed by actuating the jaw closure lever 84 with one hand. The tissueretaining pin 280 is advanced from the fixed jaw 62 into engagement withthe movable jaw 66 to capture the lumen 55 (FIG. 33) between the jaws 62and 66. The other hand is used to guide the stapling head assembly 60into the desired position. With the jaw closure lever 84 in theintermediate or detent position, the stapling head assembly 60 can bemoved along the captured lumen 55 to the desired stapling position. Ifdesired, the jaw closure lever 84 can be returned to its inoperativeposition to return the movable jaw 66 to its fully open position and toretract the tissue retaining pin 280 into the fixed jaw 62 to allow thestapling instrument 50 to be withdrawn from the body cavity foradjustment of the articulation of the stapling head assembly 60 and thecurvature of the flexible tubular shaft 76.

When the stapling head assembly 60 is located in the desired staplingposition on the lumen 55, the jaw closure lever 84 is moved to its fullyclamped position (FIG. 15) to completely close the jaw 66 to clamp thelumen 55 between the staple cartridge 64 and the anvil 68. Next, thefiring safety lever 88 is released to enable the firing trigger 86 to beactuated. The firing trigger 86 is grasped and squeezed to fire thestaples 65 in the staple cartridge 64. As shown in FIGS. 34 and 35, thestaples 65 are advanced into engagement with the anvil 68 and are formedinto a B-shaped configuration to staple the tissue lumen 55 together.The firing trigger lever 86 is locked to the jaw closure lever 84 oncethe staples 65 are fully fired. The lumen 55 is transected by usingright angle scissors or by running a scalpel along the cutting guidesformed at the longitudinal edges of the staple cartridge 64 or the anvil68. The jaws 62 and 66 are unclamped from the lumen 55 by pushing thebase of the closure lever 84 forward. With the jaws 62 and 64 unclampedand the tissue retaining pin 280 retracted, the stapling instrument 50is removed from the body cavity.

Referring to FIGS. 1 and 14, during the closure of the staplinginstrument 50 by actuation of the jaw closure lever 84, the forcesapplied by hand to the depending lever portions 122 of the closure leverplates 114 are transmitted by the fingers 165 and the closure controllinkage 154 to the closure cable 170. The force applied to the closurecable 170 is transmitted via the cable anchor 272 to the dependingflange 268 (FIG. 11) of the insert member 251 to pull the movable jaw 66toward the fixed jaw 62. Initially, the movable jaw 66 is pivoted aboutthe slidable roller pin 254 into an upright position (FIG. 16). The jawplates 240 are guided in movement relative to the base members 232 bythe roller pin 254 which slides and rotates in the slots 256 and 258 andby the bearing pin 234 and the inclined portions 262 of the guide slots260.

As the movable jaw 66 is pivoted into the upright position, the camfingers 246 engage the corresponding cams 294 and pivot the pinplacement arms 290 counterclockwise, as viewed in FIG. 9, about thepivot pins 292. The pin placement arms 290 bend the cantilever springarms 284 forward to extend the tip portion 282 of the tissue retainingpin 280 through the opening at the top of the staple cartridge 64 andinto the notch 298 at the top of the anvil 68. At this point, as shownin FIG. 16, the bearing pin 234 is positioned at the juncture betweenthe longitudinal portion 261 and the inclined portion 262 of the guideslot 260. Also, as shown by phantom lines in FIG. 15, each of the pins158 moves along the upper section 161 of the corresponding Z-shapedguide slot 160 and drops into a detent position engaging the shoulder159 in the lower section 162 of the guide slot 160. The compressionreturn spring 274 (FIG. 11) is slightly compressed to exert a returnforce on the jaw closure cable 170 to hold the pins 158 in the detentposition against the shoulders 159. The tip portion 282 of the tissueretaining pin 280 extends across the gap between the staple cartridge 64and the anvil 68 to capture the lumen 55 therebetween. The tissueretaining pin 280 prevents the partially closed jaws 62 and 66 fromslipping off the lumen 55 as the stapling head assembly 60 is movedalong the captured lumen 55 to the desired stapling position.

After the movable jaw 66 is pivoted into the upright position, thebearing pin 234 is slidably received in the longitudinal portions 261 ofthe guide slots 260 to allow the jaw plates 240 to slide longitudinallyrelative to the fixed jaw 62. Next, as shown by solid lines in FIG. 15,the jaw closure lever 84 is moved to its fully closed position withinthe slot 98 between the depending handle grips 96 of the actuator handleassembly 80. The control linkage 154 is pulled rearwardly and the pins158 travel rearwardly along the lower sections 162 of the Z-shaped guideslots 160. As the movable jaw 66 is pulled closer toward the fixed jaw62, the tip of the anvil 68 moves into engagement with a tissue stop 340at the top of the staple cartridge 64. Thereafter, the movable jaw 66pivots slightly about the tissue stop 340 until the bearing pin 234 isengaged by the distal ends of the guide slots 260 (FIG. 17). Thisbottoming out point occurs before the jaw closure lever 84 reaches theend of its travel. As the jaw closure lever 84 completes its stroke, thehigh mechanical advantage of the over-center control linkage 154stretches the closure cable 170 and applies a high force, approximately200 pounds, to pre-load the stapling jaw assembly 60 into the closedposition. This high pre-load force resists the staple forming forcesencountered during the firing of the staples 65 in the staple cartridge64.

During the motion of the jaw closure lever 84, the staple firing trigger86 is deployed from a substantially horizontal inoperative position(FIG. 2) into a substantially vertical firing position (FIG. 15) so thatthe staple firing trigger 86 can be grasped by the surgeon for firing ofthe stapling instrument 50. The pivot axis for the staple firing trigger86 is provided by the pivot pins 128 on the firing trigger plate 126which are received in the pivot holes 130 formed in the closure leverplates 114. As the jaw closure lever 84 is drawn backward, the staplefiring trigger 86 is carried backward with the jaw closure lever 84 andthe deployment pins 136 travel along a fixed cam track defined by thecam slots 140 formed in the chassis plates 102. The cam slot 140 isshaped such that the staple firing trigger 86 remains substantiallyhorizontal until the jaw closure lever 84 reaches the detent position,after approximately 20 percent of the closure travel.

Initially, as shown in FIG. 6, each of the deployment pins 136 movesdownwardly and rearwardly along an inclined cam track section 350 of thecorresponding cam slot 140. As shown by phantom lines in FIG. 15, whenthe jaw closure lever 84 arrives at the detent position, each pivot pin158 drops downwardly into engagement with the shoulder 159 in thecorresponding Z-shaped guide slot 160 and the deployment pin 136 arrivesat the bottom of the inclined cam track section 350. When the jawclosure lever 84 is moved past the detent position, each pivot pin 158is moved backward along the proximal section 162 of the Z-shaped guideslot 160 and each deployment pin 136 travels along a curved cam tracksection 352 which forces the staple firing trigger 86 to rotate aboutthe pivot pins 128 to the substantially vertical firing position. Aslong as the deployment pin 136 is located in either the inclined camtrack section 350 or the curved cam track section 352, the movement ofthe jaw closure lever 84 can be reversed to return the staple firinglever 86 to the substantially horizontal position.

During the deployment of the staple firing trigger 86, the motion of thetrigger firing plate 126 relative to the closure plate 114 is restrictedby the deployment pins 136 which are captured in the cam track sections350 and 352. Thus, any manual pulling force applied to the staple firingtrigger 86 during its deployment merely urges the jaw closure lever 84toward its closed position. Since the deployment pins are captured inthe cam track sections 350 and 352, the staple firing lever 86 cannot beactuated to fire the staples in the staple cartridge 64. When the jawclosure lever 84 is pulled to its fully closed position, the pivot pins158 are located at the proximal ends of the Z-shaped guide slots 160 andeach of the deployment pins 136 is located at a rear corner 354 of thecorresponding cam slot 140 where the curved cam track sections 352 and356 intersect. After the firing safety lever 88 is released, the staplefiring trigger 86 is free to pivot relative to the jaw closure lever 84to actuate the stapling head assembly 60.

Next, the staple firing trigger 86 is grasped and pulled toward the jawclosure lever 84. The staple firing plate 126 is pivoted about the pivotpins 128 in a counter-clockwise direction, as viewed in FIG. 10. Thearc-shaped slots 138 in the jaw closure plates 114 are aligned with thecurved cam track sections 356 of the cam slots 140 in the chassis plates102. The deployment pins 136 are free to travel along the curved camtrack sections 356 to allow the staple firing trigger 86 to pivot to itsfully closed position to actuate the stapling head assembly 60. As thestaple firing plate 126 is pivoted toward its fully closed position, thefiring cable 148 is wrapped around the enlarged proximal end portion 134to take up the slack in the firing cable 148. When the staple firingtrigger 86 is moved to its fully actuated position, the firing cable 148is pulled around the pulley 120 and placed in tension to actuate thefiring cam 324 in the stapling head assembly 60. The firing of thestaples in the staple cartridge 64 is explained in more detail below.

Once the stapling instrument 50 is fired, a pair of detents 360 (oneshown in FIG. 6) on the interior of the firing trigger shroud 132 aresnap-fit into a corresponding pair of apertures 362 in the closure levershroud 124 to attach the stapling firing trigger 86 to the jaw closurelever 84. This snap feature cannot be reversed by the surgeon so thatthe staple firing trigger 86 remains attached to the jaw closure lever84 indicating that the stapling instrument 50 has been fired. Thestapling head assembly 60 is opened after firing by pushing on a contactpad 364 at the tip of the closure lever shroud. The jaw closure lever 84and the stapling firing trigger 86 move together as a single unit into asubstantially vertical open position. During this motion of the jawclosure lever 84 and the staple firing trigger 86, the deployment pins136 travel along the final curved cam track section 358 of the cam slots140. With the stapling head assembly open, each pivot pin 158 isreturned to the distal end of the upper section 161 of the correspondingZ-shaped guide slot 160 and each of the deployment pins 136 is moved tothe distal end of the curved cam track section 358 of the correspondingcam slot 140.

In order to reset the stapling instrument 50, after a test firing at thefactory, the jaw closure lever 84 and the staple firing trigger 86 aremoved into the closed position and the detents 360 are disengaged fromthe apertures 362 to allow the staple firing trigger 86 to move forwardrelative to the jaw closure lever 84 into the deployment position.Thereafter, the jaw closure lever 84 is moved forward to its openposition and the staple firing trigger 86 is returned to itssubstantially horizontal inoperative position.

During the actuation of the stapling head assembly 60, firing forces aretransmitted from the actuator handle assembly 80 to the stapling headassembly 60 via the firing cable 148. The geometry of the firing cable148, the firing trigger plate 126, the cable pulley 120 and the closurelever pivot 110 is selected such that, during the closure and deploymentof the staple firing trigger 86, the cable length remains substantiallyconstant. To fire the stapling instrument 50, the staple firing trigger86 is deployed by actuating the jaw closure lever 84 to its partiallyclosed position. Then the firing safety lever 88 is disengaged from thestaple firing trigger 86. By pulling the staple firing trigger 86, thefiring cable 148 is placed in tension so that the forces applied fromthe stapling firing plate 126 to the jaw closure plates 114 via thepivot pins 128 tend to pull the jaw closure lever 86 further closed.This safety feature precludes the possible opening of the jaw closurelever 84 during the firing of the staples 65 from the staple cartridge64.

In the actuation of the stapling head assembly 60, the firing cam 324.ispulled downwardly by the firing cable 148 and the staple driver 320 isadvanced by two cam mechanisms. First, the firing cam pins 326 travel inthe firing cam slots 328 which are inclined downwardly and forwardly atan angle of 15° relative to the vertical axis 52. Second, the inclinedcam surfaces 332 and 334 on the firing cam 324 and the staple driver320, respectively, engage each other and result in further displacementof the staple driver as the firing cam 324 is pulled downwardly. Thisdual cam mechanism achieves a high mechanical advantage in a compactspace. The geometry of the two cam mechanisms is such that the firingcam 324 and the staple driver 320 move into engagement at the flat camsurfaces 336 and 338 before the travel of the firing cam pins 326 in thefiring cam slots 328 is completed. This arrangement allows the stapledriving mechanism to operate with two mechanical advantages, i.e, a lowmechanical advantage during the initial stroke when both cam mechanismsare engaged and a high mechanical advantage toward the end of the strokewhen only the firing cam slots 328 are engaged. The changeover in theoperation of the dual cam mechanisms occurs at a low point in theforming force/deflection curve for the staples. This operationeffectively minimizes the firing cable force at all points in the firingstroke of the staple forming mechanism.

Referring to FIG. 18, the staple cartridge 64 comprises an elongated,generally rectangular housing 370, preferably made of plastic, whichincludes a plurality of staple receiving slots or pockets 372 arrangedin one or more longitudinal rows. Preferably, the staple receivingpockets 372 are arranged in two longitudinal rows (FIG. 20) so that therows of staples 65 are staggered relative to each other. As shown inFIG. 18, the anvil 68 comprises an elongated, channel-shaped member madeof metal, e.g., stainless steel. The anvil 68 includes a pair oflongitudinally extending rows of staple forming grooves 366 (FIG. 19)which are arranged in pairs aligned with the staple receiving pockets372 in the staple cartridge 64. The grooves 366 are shaped to form thestaples 65 into a B-shaped configuration when the staple driver 320 isadvanced to drive the staples 65 against the anvil 68.

In the embodiment of the staple cartridge 64 shown in FIG. 20, theright-hand row has nine staple receiving pockets 372 and the left-handrow has ten pockets 372. It will be understood by persons skilled in theart that other arrangements of staple receiving pockets 372 can beemployed. For example, the staple cartridge 64 may include a single rowof staple receiving pockets 372, or three or more staggered rows ofstaple receiving pockets 372. Similarly, the anvil 68 can be modified toinclude a single row of staple forming grooves 366, or three or morerows of staple forming grooves 366.

As shown in FIG. 24, the staple receiving pockets 372 in each row areseparated by a series of horizontal ribs 374 which serve as guides forthe staples 65. The staple cartridge housing 370 includes a pair ofelongated flanges 376 (FIG. 20) extending along its opposite sides. Theflanges 376 are provided with longitudinal grooves 378 (FIG. 21) whichserve as cutting guides for a surgical knife or scalpel. An elongatednotch 380 (FIGS. 23 and 24) extends horizontally across the bottom ofthe staple cartridge housing 370 for receiving a corresponding ridge 382(FIG. 19) formed on the spring housing 266 of the pilot member 250. Thechannel 380 and the ridge 382 act as a guide mechanism for aligning theanvil 68 with the staple cartridge 64 when the movable jaw 66 is pulledtoward the fixed jaw 62.

Referring to FIGS. 25-28, the staple driver 320 includes a plurality ofstaple driving fingers 390 mounted on a central connecting web 392 andarranged in two staggered rows corresponding to the rows of staplereceiving pockets 372 in the staple cartridge housing 370. The distalend of each staple driving finger 390 has a substantially hexagonalcross section and is slidably received in one of the staple formingpockets 372 which also has a substantially hexagonal shape. Each of thestaple driving fingers 390 (FIG. 25) of the staple driver 320 isslidably received between an adjacent pair of ribs 374 (FIG. 24) on thestaple cartridge housing 370. At its distal end, each of the stapledriving fingers 390 has a pair of staple engaging ridges 394 (FIG. 27)separated by a transversely extending notch 396. A pair of staplereceiving grooves 398 extends longitudinally across the ridges 394 onopposite sides of each notch 396.

Referring to FIGS. 28 and 29, a cam insert 400 can be sandwiched betweenthe staple driving fingers 390 on the proximal side of the connectingweb 392 to strengthen the staple driver 320. The proximal edge of theinsert 400 has a pair of sloped cam surfaces 402 and a pair of flat camsurfaces 404 which are contoured to correspond to the cam surfaces 334and 338 (FIGS. 27 and 28) at the proximal ends of the staple drivingfingers 390 on the staple driver 320.

In the preferred embodiment of the surgical stapling instrument 50, thefiring cable 148 and the closure cable 170 each have a counter-twistedconstruction which minimizes the changes in length of the cables 148 and170 due to rotation of the support shaft assembly 70 about thelongitudinal axis 54. The construction of the firing cable 148 and theclosure cable 170 consists of multiple filaments or wires, preferablymade of stainless steel, which are twisted together. A preferredembodiment of the cable construction is shown in FIGS. 46 and 47, whichis equally applicable to both cables 148 and 170.

Referring to FIG. 46, the closure cable 170 has a multiple filamentconstruction consisting of three multi-filament strands 410 which aretwisted together in a helical arrangement with a right-hand twist. Eachof the three strands 410 includes nineteen filaments or wires which aretwisted together in a helical arrangement with a left-hand twist. Asshown in FIG. 47, each strand 410 consists of a one-by-seven corecomprising a center wire 412 covered by six wires 414 twisted in aleft-hand direction about the center wire 412. A covering of twelvefilaments or wires 416 is twisted in a left-hand direction about theone-by-seven core. The three strands 410, each including nineteenfilaments or wires, are twisted together with a right-hand twist toprovide a finished cable construction consisting of fifty-sevenfilaments or wires.

In the preferred embodiment, the center wire 412 is made of stainlesssteel, 0.0071 inch in diameter, ASTM F138-86 Grade 2. The six wires 414are made of stainless steel, 0.0063 inch diameter, ASTM F138-86 Grade 2,twisted in a left-hand direction ("S" twist) about the center wire 412in a range of 4.8 to 5.5 twists per inch. The twelve wires 416 are madeof stainless steel, 0.0056 inch in diameter, ASTM F138-86 Grade 2,twisted in a left-hand direction ("S" twist) around the core in a rangeof 2.8 to 3.2 twists per inch. The finished cable consists of the threestrands 410 of stainless steel wires which are twisted together in aright-hand direction ("Z" twist) in the range of 2.0 to 2.3 twists perinch.

The multi-filament, counter-twisted cable construction described aboveis insensitive to rotation so that the cables 148 and 170 maintain asubstantially constant length when the support shaft assembly 70 isrotated about its longitudinal axis 54. The counter-wound constructionof the multi-filament strands 410 tends to balance the shortening andlengthening effects on the cables 148 and 170 due to rotation of theshaft assembly 70 so that a substantially constant cable length ismaintained within the ±170° rotational range of the support shaftassembly 70. For example, in the above cable construction, it is desiredthat the length of the cables 148 and 170 be maintained constant within±0.005 inch over the ±170° range of rotation. Alternatively, if aconventional cable construction is used, a suitable cam surface (notshown) can be provided between the proximal end of the tubular shaft 74and the stop plate 151 to compensate for changes in length of the cables148 and 170 due to rotation of the support shaft assembly 70.

The invention in its broader aspects is not limited to the specificdetails of the preferred embodiments shown and described, and thoseskilled in the art will recognize that the invention can be practicedwith modification within the spirit and scope of the appended claims.

We claim:
 1. A surgical instrument for applying one or more surgicalfasteners to tissue, comprising:a fastener applying assembly including afastener holder for receiving one or more surgical fasteners, an anvilfor clamping the tissue against said fastener holder, and a driver fordriving the fasteners from said fastener holder into the tissue clampedby said anvil against said fastener holder; an actuator handle assemblyincluding a housing and means for actuating said driver; and a shaftassembly for mounting said fastener applying assembly to said housingand said actuator handle assembly, said shaft assembly having alongitudinal axis and having proximal and distal ends and including arigid support shaft section not enclosed by said housing, said rigidsupport shaft section connected to a flexible shaft section adapted tobe bent in any radial direction relative to the longitudinal axis ofsaid shaft assembly.
 2. The surgical instrument of claim 1, wherein:saidflexible shaft section is located at the distal end of said shaftassembly adjacent to said fastener applying assembly.
 3. The surgicalinstrument of claim 1, which includes:a pivot connection at the distalend of said shaft assembly for supporting said fastener applyingassembly to pivot about an axis transverse to the longitudinal axis ofsaid shaft assembly.
 4. The surgical instrument of claim 3, wherein:saidpivot connection includes detent means for maintaining said fastenerapplying assembly in predetermined angular positions relative to thelongitudinal axis of said shaft assembly.
 5. The surgical instrument ofclaim 1, wherein:said flexible shaft section is adapted to retain itsbent shape and to resist deflection when said fastener applying assemblyis actuated.
 6. The surgical instrument of claim 1, wherein:said shaftassembly is rotatable about its axis to orient said fastener applyingassembly in different angular orientations relative to said actuatorhandle assembly.
 7. The surgical instrument of claim 6, whichincludes:means for locking said shaft assembly in different angularorientations relative to said actuator handle assembly.
 8. The surgicalinstrument of claim 1, wherein:said flexible shaft section is limited toa predetermined range of bending angles relative to the longitudinalaxis of said shaft assembly.
 9. The surgical instrument of claim 1,wherein:said fastener holder is adapted to receive a plurality ofsurgical fasteners arranged in one or more rows.
 10. A surgical staplinginstrument for applying one or more surgical staples to tissue,comprising:a stapling head assembly including a staple holder forreceiving one or more surgical staples, an anvil for clamping the tissueagainst said staple holder, and a staple driver for driving the staplesfrom said staple holder into the tissue and against said anvil; anactuator handle assembly including a housing and first actuator meansfor moving said anvil into a tissue clamping position and secondactuator means for actuating said staple driver; and a shaft assemblyfor mounting said stapling head assembly to said housing and saidactuator handle assembly, said shaft assembly having a longitudinal axisand having proximal and distal ends and being rotatable over itslongitudinal axis to orient said stapling head assembly in differentangular orientations relative to said actuator handle assembly, and saidshaft assembly including a rigid support shaft section not enclosed bysaid housing, said rigid support shaft section connected to a flexibleshaft section adapted to be bent in any radial direction relative to thelongitudinal axis of said shaft assembly.
 11. The stapling instrument ofclaim 10, wherein:said flexible shaft section is located at the distalend of said shaft assembly adjacent to said stapling head assembly. 12.The stapling instrument of claim 10, which includes:a pivot connectionat the distal end of said shaft assembly for supporting said staplinghead assembly to pivot about an axis transverse to the longitudinal axisof said shaft assembly.
 13. The stapling instrument of claim 12,wherein:said pivot connection includes detent means for maintaining saidstapling head assembly in predetermined angular positions relative tothe longitudinal axis of said shaft assembly.
 14. The staplinginstrument of claim 10, wherein:said flexible shaft section is adaptedto retain its bent shape and to resist deflection when said staplinghead assembly is actuated.
 15. The stapling instrument of claim 10,which includes:means for locking said shaft assembly in differentangular orientations relative to said actuator handle assembly.
 16. Thesurgical instrument of claim 10, wherein:said flexible shaft section islimited to a predetermined range of bending angles relative to thelongitudinal axis of said shaft assembly.
 17. The surgical instrument ofclaim 16, wherein:said first actuator means includes a closure cableextending through said shaft assembly for pulling said anvil toward saidfastener holder to clamp the tissue therebetween.
 18. The surgicalinstrument of claim 17, wherein:said second actuator means includes afiring cable extending through said shaft assembly for actuating saidstaple driver to drive the staples from said staple holder and to formthe staples against said anvil.
 19. The stapling instrument of claim 10,wherein:said staple holder is adapted to receive a plurality of surgicalstaples arranged in one or more rows.